Prediction of dissolved oxygen in pond culture water based on K-means clustering and gated recurrent unit neural network

• Published in: Aquacultural engineering Vol. 91; p. 102122
• Main Authors: Cao, Xinkai, Liu, Yiran, Wang, Jianping, Liu, Chunhong, Duan, Qingling
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2020
• Subjects: Dissolved oxygen prediction; Gated recurrent unit neural network; K-means clustering; Pond culture; Gated recurrent unit neural network; Dissolved oxygen prediction; Pond culture; K-means clustering
• ISSN: 0144-8609; 1873-5614
• DOI: 10.1016/j.aquaeng.2020.102122

•Propose a prediction method for predicting the dissolved oxygen in pond culture.•Improve the clustering similarity calculation method according to the characteristics of dissolved oxygen time series.•Design a sample set processing method for flexible selection of predictive variables and predictive time.•Improve the accuracy of prediction in different time. Dissolved oxygen in water is an important ecological factor in ensuring the healthy growth of aquatic products, as hypoxic stress is known to restrict the growth of aquatic products. The accurate monitoring and prediction of dissolved oxygen is the key to precise regulation and control of pond aquaculture water quality. The current dissolved oxygen prediction model has some limitations, such as a short prediction period and inadequate prediction accuracy for actual production demands. Therefore, a prediction model of dissolved oxygen in pond culture was proposed based on K-means clustering and Gated Recurrent Unit (GRU) neural network. Firstly, the key factors affecting the changes in dissolved oxygen were selected by principal component analysis (PCA). The dissolved oxygen time series was then subjected to K-means clustering, and the dissolved oxygen prediction model was constructed using GRU. To improve the clustering effect, we enhanced the similarity calculation for the time series based on the variation of dissolved oxygen. This process combined the Euclidean distance with the dynamic time-warping distance. The proposed method can predict the dissolved oxygen content of aquaculture water over different time intervals according to the demands of real-world scenarios. The average absolute error of the 30-min interval model was 0.264, and the mean absolute percentage error was 3.5 %. Experimental results indicated that the proposed method achieves higher prediction accuracy and flexibility than the conventional approach.